Apparatuses for filtering and/or purifying water, which have a housing or canister having a filtration chamber formed therein and a filtration device, such as a filtration matrix or a microfiltration matrix, mounted in the filtration chamber for filtering and/or purifying the water passing through it, are known. Water to be filtered and/or purified may be pumped into the filtration chamber of such apparatuses where the water may pass through the filtration device mounted in the filtration chamber to filter and/or purify the water. After passing through the filtration device, which results in filtering and/or purifying the water, the water which has been filtered and/or purified may exit the apparatus through an outlet port. Typically, in such apparatuses, the filtration device divides the filtration chamber into two zones, a first zone for receiving water to be filtered and/or purified and a second zone for receiving water that has been filtered and/or purified by moving from the first zone into the second zone by passing through the filtration device. The second zone is in fluid communication with the outlet port from the housing or canister from which the water that has been filtered and/or purified exits the apparatus for filtering and/or purifying water. An example of one such apparatus is manufactured and sold by General Ecology, Inc., of Exton, Pa., under the trademark FIRST NEED, which has been well received in the marketplace as being very effective in providing potable water.
Due to the nature of the filtration device in such apparatuses, appropriate care should be taken to avoid dropping such apparatuses. If such apparatuses are dropped from too high of a height onto a hard surface, the filtration device may be damaged, thereby creating a pathway through the filtration device for untreated water to pass without being filtered and/or purified.
During use of apparatuses like General Ecology's FIRST NEED apparatus for filtering and/or purifying water, dirt and debris contained in the water to be filtered and/or purified tends to build up in the first zone of the filtration chamber on the surface of the filtration device facing the first zone of the filtration chamber, as well as in the first zone of the filtration chamber between the wall of the filtration chamber in the first zone and the filtration device. Currently, to remove such dirt and debris that builds up on the filtration device in the first zone of the filtration chamber and that builds up in the first zone of the filtration chamber between the walls of the filtration chamber and the filtration device, such apparatuses are backwashed. That is, purified water is pumped in a reversed direction through the apparatus for filtering and/or purifying water to remove dirt and debris built up on the surface of the filtration device in the first zone of the filtration chamber and built up in the first zone of the filtration chamber between the wall of the filtration chamber and the filtration device. Specifically, when backwashing, water is pumped into and through the outlet port into the second zone of the filtration chamber, then from the second zone of the filtration chamber through the filtration device into the first zone of the filtration chamber that receives the water to be filtered and/or purified when the apparatus is being used to filter and/or purify water, and then from the first zone of the filtration chamber through the inlet port of the apparatus to exit the apparatus taking with it the dirt and debris that had built up in the apparatus. A drawback with such backwashing is that it creates a risk of damaging the filtration device since pumping water too hard in a reverse direction of flow through the filtration device (e.g., through the filtration device from the second zone of the filtration chamber into the first zone of the filtration chamber) may damage the filtration device. Moreover, if water that has not been filtered and purified is used to backwash the apparatus for filtering and/or purifying water, the backwash procedure places water that has not been filtered and/or purified in the second zone of the filtration chamber and outlet port of the apparatus, which is undesirable.